The object of the present invention is to provide an improved anchor adjuster for adjusting one or more rail-mounted anchors on a rail toward a tie.
A rail anchor clamps onto a railway rail and is positioned to abut a vertical face of a tie whereby resistance is provided against longitudinal movement of a rail relative to the supporting tie.
For many years, there have been machines for setting, applying and removing rail anchors. This procedure involves both placing rail-mounted anchors in close abutting relation with opposite vertical faces of a tie when installing the anchors and/or tie, as well as shifting the tie-abutting rail-mounted anchors lengthwise of the rail so that a tie remover can withdraw the tie longitudinally from beneath the rail to replace the tie. Equipment for spreading anchors is shown in Quella U.S. Pat. No. 4,890,558. The adjusting of anchors into tie-abutting positions generally can be accomplished with a limited degree of efficiency with the use of a rail anchor relocator, such as that shown in Miller U.S. Pat. No. 3,117,531.
Utilization of equipment of the type shown in Miller has proven effective for many years, but, however, is subject to some limitations. The relocator assembly in Miller is suspended from a chain during transport of the machine and is allowed to fall under the acceleration of gravity to an operative position. To sufficiently engage an anchor for relocating, it is necessary that the assembly be lowered to a position some distance below the base of the rail. The rocks and gravel which comprise railway ballast for rigidifying the ties is frequently very densely packed and prevents the necessary downward deployment of the assembly. When this type of ballast is encountered, the apparatus of Miller is inadequate to adjust the anchors.
Also, because of the minimal tolerances and tight fit of the anchors on the rails, substantial force is required to shift the anchors along the rails toward the tie. Miller discloses a pin-and-groove linkage arrangement which imparts minimal horizontal forces to the anchors during a portion of the stroke of a hydraulic driving cylinder. The resulting mechanical advantage requires a high-powered hydraulic actuator which inherently must provide non-linear adjusting force versus actuator stroke characteristics.